molecular biology

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DNA is the bedrock of our genetic identity. It encodes physical and mental traits in our genes and it is generally unchanging and the same in all cells. There are ‘epigenetic’ aspects, some of which are still puzzling, that appear to carry over between generations, which are not due to the modification of DNA sequence. (Other posts have explored epigenetics.) But DNA sequence is the default carrier of our genetic identity.

Although the DNA in our cells is largely unchanging and the same in every cell, neither of those features is strictly true.… Read the rest “the goldilocks zone: Mutation, Cancer, and Evolution”

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(Vials of SARS-CoV-2 vaccine).

The coronavirus SARS-CoV-2, the cause of COVID-19, has quickly spread and caused devastation throughout the world. The medical science community has responded vigorously, with better treatments, recommended changes in social behavior, and, of particular importance, effective vaccination programs. Of the immunization protocols that have been developed, the novel mRNA-based vaccines have captured the scientific spotlight; they are the first mRNA vaccines to be licensed for human use.

A new way to immunize

In principle, the mechanism by which mRNA vaccines create immunity to SARS-CoV-2 is straightforward.… Read the rest “A BRIEF HISTORY OF MESSENGER RNA”

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The agitated detective barks, “I need that DNA now. I have to know if we’ve got the killer in custody. I don’t give a damn how busy you are . . . ” We’ve all been there, on the edge of the couch, watching a cop show on TV and hoping that the magic of DNA testing will give a clear answer to the question “DidHeDoIt?” And indeed, DNA fingerprinting, more accurately ‘DNA profiling’, has transformed crimefighting.… Read the rest “The Unanticipated Birth of DNA profiling”

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Gel electrophoretic separation of DNA fragments containing Variable Numbers of Tandem Repeats. Each vertical lane contains one DNA sample. PCR-amplified fragments have been labeled, with different probes having different fluorescent labels. The red bands are internal calibration markers. The positions of the bands reflect their different mobilities, which in turn reflect their lengths (larger fragments move more slowly in electrophoresis). Capillary electrophoresis and automatic recording are used today instead of gel electrophoresis.

DNA profiling resulted from the convergence of scientific curiosity, technological advances, and the desire to provide a social benefit.… Read the rest “New and improving DNA profiling continues to impress and surprise”